1. Field of Invention
The present invention relates to a mounting structure in combination with a tube for mounting a wire harness, and the wire harness. The wire harness is preferable mounted to an automobile. In particular, in a movable wire harness mounted to extend from an automobile body side to a door side and that is extensibly/retractably movable during opening and closing of the door, the present invention relates to an improvement of an exterior member and an engaging mechanism of the wire harness. Further, the present invention relates to a method for making the wire harness.
2. Description of Related Art
As shown in FIGS. 5(A) and 5(B), a wire harness W/H mounted to extend from an automobile body 1 to a back door 2 is fixed at the automobile body 1 side. The back door 2 moves up and down during an opening and closing operation of the back door. The wire harness W/H should be pulled out toward the back door 2 side, when the back door is opened. Meanwhile, when the back door 2 is closed, the wire harness W/H should be retracted toward the automobile body 1 side. Accordingly, a housing 3 is provided at the automobile body side for extending and retracting the wire harness. The wire harness W/H has sufficient slack to be bent or meandered and stored in the housing 3, and is fixed at the automobile body I side and the back door 2 side by clips 5 and 4, respectively. Further, a spring 6 is mounted between the wire harness W/H and the housing 3 so that the wire harness W/H is forced to be retracted into the housing 3.
According to the structure described above, the wire harness W/H is pulled out from the housing 3 against the force of the spring 6, when the back door 2 is opened. Moreover, when the back door 2 is closed, the wire harness is retracted into the housing 3 by the spring 6.
Since the above-described wire harness W/H is mounted between the automobile body 1 and the back door 2, a portion of the wire harness W/H that is pulled out from the housing 3 and is attached to the back door 2 is exposed to a passenger compartment side. A conventional wire harness W/H is made of electric wires wrapped with tape T1. However, the tape T1 may be broken by interference of objects, and thus, the wire harness is not sufficiently protected. In addition, the appearance is not good.
Further, during an extending or retracting operation of the wire harness, tensile loads are intensively applied to the clip 4, which fixes the wire harness W/H on the back door 2, and to the clip 7, which fixes the spring 6 to the wire harness W/H. Accordingly, the wire harness can be easily separated from the clips 4 and 7. In other words, when the clips 4 and 7 are band-type clips as shown in FIG. 6(A), the wire harness might escape from the band. When the clips 4 and 7 are strip-type clips, as shown in FIG. 6(B), and the wire harness is fixed to the strip of the clips by wrapping tape T2, the tape T2 might be torn off. When the wire harness W/H is separated from the clip 4, which fixes the wire harness W/H to the back door 2, the wire harness W/H hangs down toward the passenger compartment side and does not smoothly follow the opening and closing operation. Further, when the wire harness is separated from the clip 7 that fixes the wire harness W/H to the spring 6, the spring force is not applied to the wire harness, and thus, an extending and retracting operation of the wire harness may not be performed.
The present invention is provided to eliminate the above-described drawbacks, i.e., to improve protection and appearance of the wire harness, and further, to securely fix the wire harness to the back door side and to the spring even during extending and retracting operation of the wire harness.
To achieve the above and/or other goals, the present invention provides, in combination with a tubular member, a mounting structure for the tubular member. The combination includes an attachment member having a strip portion mounted on an outer peripheral surface of the tubular member, and a heat shrinkable tube surrounding a part of the strip portion of the attachment member and the tubular member. The heat shrinkable tube is contracted by heating. Thus, heating causes the heat shrinkable tube to contract so that the strip portion is fixed to the tubular member.
Preferably, the tubular member is a mesh tube. The mesh tube provides better appearance. The tubular member preferably is non-extensible, and the diameter of the tubular member can be enlarged when the tubular member is axially compressed.
Further, preferably, a hot-melt adhesive is provided on an inner peripheral surface of the heat shrinkable tube. When the hot-melt adhesive is used in combination with the mesh tube, heating causes the hot-melt adhesive to melt and permeate into a mesh of the mesh tube and causes the heat shrinkable tube to contract, so that the strip portion is tightly fixed to the mesh tube.
An elongated member can be inserted into the tubular member, to form a wire harness, for example. The elongated member can be at least one of an electric wire and an optical fiber.
The tubular member is suitable to be mounted for movement, in particular, the tubular member is mounted between an automobile body and a door attached to the automobile body.
The attachment member can be a clip to engage the tubular member with stable points, however, the attachment member can have any desired configuration, for example, a connector that connects two tubular members in parallel.
In the combination, the heat shrinkable tube may be a pair of short length tubes provided at opposite ends of the strip portion in a longitudinal direction. Alternatively, the heat shrinkable tube may have a length substantially the same as a length of the strip portion and a hole is provided in a peripheral surface of the heat shrinkable tube, so that the engaging portion projects through the hole toward the exterior.
In another aspect of the present invention, a wire harness including at least one of an electric wire and an optical fiber is provided. The wire harness further includes a tubular member into which the at least one of the electric wire and the optical fiber is inserted, and at least one attachment member having a strip portion mounted on an outer peripheral surface of the tubular member. A heat shrinkable tube surrounds the strip portion of the attachment member and the tubular member, and heating contracts the heat shrinkable tube. Thus, heating causes the heat shrinkable tube to contract so that the strip portion is fixed to the tubular member.
Preferably, the tubular member is a mesh tube. The mesh tube can be made of suitable insulating resin strands, such as nylon or PET, knitted or woven in a cylindrical shape. The tubular member is not extensible, and the diameter of the mesh tube and the mesh size is enlarged when the mesh tube is compressed in an axial direction to enable insertion of the at least one of an electric wire and an optical fiber.
When a set of electric wires and/or optical fibers of a wire harness is inserted into the mesh tube, superior protective function can be achieved as compared with tape wrapping, and appearance of the wire harness exposed to, for example, the inside of the passenger compartment can be improved. In addition, since the diameter of the mesh tube is enlarged when the mesh tube is compressed in the axial direction, the electric wires and/or optical fibers can be easily inserted into the mesh tube.
Preferably, hot-melt adhesive is provided on an inner peripheral surface of the heat shrinkable tube. When the hot-melt adhesive is used with a mesh tube, heating causes the hot-melt adhesive to melt and permeate into the mesh of the mesh tube to provide plural anchor points. Accordingly, the strip portion is fixed to the mesh tube more tightly.
The attachment member can be a clip.
The wire harness of the present invention may be used between any movable and stationary surfaces, but is particularly suitable to be mounted for movement. For example, the wire harness can be provided between an automobile body and a door attached to the automobile body. The door may be a back door that is opened and closed in a vertical direction. Further, a portion of the wire harness is stored in a housing provided on the automobile body when the door is closed and is pulled out from the housing when the door is opened. In this case, a pair of clips are provided on the tubular member. Each has an engaging portion projecting from a strip portion. One of the pair of the clips engages with an elastic member provided between the tubular member and the housing so that the tubular member is retracted inside of the housing. The other clip engages with the door.
A coil spring is preferably used as the elastic member. A hook provided at one end of the coil spring is hooked in a hole provided in the engaging portion of the clip. The clip, fixed to the mesh tube by a heat shrinkable tube on which the hot-melt adhesive is applied, is used to fix the wire harness to the door. However, the clip may also preferably be used to fix the wire harness to the elastic member (spring).
When an attachment member (a band-type or a strip-type clip) is fixed to the outer peripheral surface of the mesh tube by a conventional method, since the mesh tube has a low friction drag, i.e., is easy to slip, the same problem occurring in the conventional wire harness wrapped with tape still occurs. In other words, when a band-type clip is used, the band may slide along or slide off the mesh tube. When a strip-type clip is used, the tape wrapping the clip and the wire harness may be torn off. Accordingly, in the present invention, a heat shrinkable tube, preferably with hot-melt adhesive, is used to surround a strip portion of the strip-type clip and the mesh tube. When heat is applied to the heat shrinkable tube, the hot-melt adhesive melts and permeates into the mesh of the mesh tube, and the heat shrinkable tube contracts to be fixed to the strip portion and the mesh tube. Thus, the strip-type clip is firmly fixed to the mesh tube.
The heat shrinkable tube may be a pair of short length tubes provided at opposite ends of the strip portion in a longitudinal direction. Alternatively, the heat shrinkable tube may have a length substantially the same as a length of the strip portion and a hole is provided in a peripheral surface of the heat shrinkable tube, so that the engaging portion projects through the hole toward the exterior.
Thus, when the strip portion of the strip-type clip is fixed to the mesh tube by the hot-melt adhesive melting and permeating into the mesh of the mesh tube, and the strip portion is tightly pressed to the outer peripheral surface of the mesh tube by contraction of the heat shrinkable tube, even if a pulling-off force is applied to the mesh tube into which electric wires are inserted, the clip can be prevented from separating from the mesh tube.
In another aspect of the present invention, a method for making a wire harness is provided. In the method, at least one of an electric wire and an optical fiber is inserted into a mesh tube. A clip is mounted on the mesh tube. A heat shrinkable tube surrounds the mesh tube and the clip. Then, the heat shrinkable tube is heated to contract the heat shrinkable tube so that the clip is fixed on the mesh tube.
The method further can include providing a hot-melt adhesive on an inner peripheral surface of the heat shrinkable tube, and heating the hot-melt adhesive to melt and permeate the hot-melt adhesive into the mesh tube.